1. Technical Field
The present invention relates to a superconductive magnet that has a superconductive coil.
2. Description of the Related Art
For example, a technology in this field is disclosed in the related art. A superconductive magnet of the related art includes a cylindrical vacuum chamber, and a space is formed in a center portion of the vacuum chamber to pass therethrough in a vertical direction. A superconductive coil is disposed in the vacuum chamber to generate a high magnetic field in the space. The superconductive coil is wound around a bobbin, and the bobbin is configured to have a cylindrical inner bobbin and a pair of flanges each of which is formed in each end of the inner bobbin. Cooling means integrated with a Gifford McMahon (GM) refrigerator is provided above the superconductive coil. A cold head of the cooling means is connected to an upper flange via a cooling stage. Since the superconductive coil is cooled by the cooling means, a high magnetic field can be generated.
The superconductive magnet of the related art is applied to an apparatus that pulls up a silicon single crystal, and is used as a source of a high magnetic field in a so-called magnetic Czochralski (MCZ) method. For example, an apparatus of the related art is an apparatus that pulls up a silicon single crystal using the MCZ method. The apparatus includes a crucible that accommodates a single crystal silicon raw material, and a magnet is provided on a side of the crucible as the source of the high magnetic field. The magnet of the related art is configured to have an air-core coil that does not have the inner bobbin.